Extrusion coating compositions for woven and non-woven polyolefin substrates and articles thereof

ABSTRACT

Extrusion coating compositions for woven and non-woven polyolefin substrates are disclosed which employ an ethylene-propylene-diene terpolymer rubber, a high density polyethylene, and ethylene-propylene block copolymer and an ethylene-isobutylacrylate copolymer. Optionally, ultraviolet stabilizers, flame retardants and pigments can be added to each. Also disclosed are woven and non-woven polyolefin substrates which are coated with the above-cited extrusion coating compositions.

BACKGROUND

Extrusion coating involves the process of extruding a molten film from adie and contacting this molten film with a substrate under pressure inthe nip of two counter-rotating rolls or the like. Both of these rollscan be chill rolls, which by definition means temperature controllablerolls. Alternatively, one of these rolls can be a pressure roll, whichhas a deformable surface able to distribute pressure over an unevensurface. The pressure roll is in contact with the side not being coated,and the chill roll is in contact with the side being coated.

Extrusion coating of woven and non-woven polyolefin substrates involvesseveral problems. Some examples of such problems are extruder surging,poor coating adhesion particularly to polypropylene, and unaesthetichand for some coatings having a thickness greater than one mil. Todecrease extruder surging, which is the non-uniformity of gauge orcoating weight in the machine direction, and to increase adhesion of theextruded coating to polypropylene substrates, the melt flow rate of theextrusion coating is generally increased. However, to decreaseundesirable neck-in which is the difference between the width of the webas it exits from a die and that width at the point of contact with asubstrate, the melt flow and temperature of the extruded coating aregenerally decreased. In summary, to achieve a suitable extrusion coatingfor polyolefins and more specifically polypropylene, the range oftemperatures and flow rates that are usable must resolve a variety ofproblems which have conflicting methods of solution.

Good adhesion with extrusion coatings of low density polyethylene tohigh density polyethylene fabrics requires extrusion temperatures ofabout 600° F. in order to cause some melt oxidation. However, neitherlow density nor high density polyethylene alone can be made to adherewell to polypropylene fabrics regardless of process conditions. Surfaceprimers for polypropylene fabrics have had limited success.

In U.S. Pat. No. 3,524,759 (1970) of R. L. McConnell et al., a processfor curtain coating of flat sheets, paper, cardboard, articles of anysize or shape, etc. is disclosed. The composition employed in thatcurtain coating process was a thermoplastic composition having a meltviscosity at 190° C. of 5,000 to 125,000 cp. comprising:

(1) 40 to 99 percent by weight of a copolymer of 55 to 99 percent byweight of ethylene and 1 to 45 percent of at least one comonomerselected from the group consisting of:

(a) alkenyl alkanoates wherein said alkenyl portion contains 2-4 carbonatoms and said alkanoate portion contains 2-6 carbon atoms,

(b) alkyl acrylates, wherein said alkyl contains 1 to 8 carbon atoms,

(c) alkyl methacrylates wherein said alkyl contains 1 to 8 carbon atoms,

(d) acrylic acid,

(e) methacrylic acid, and

(2) 1 to 60 percent by weight of a crystallizable polymer of an α-olefinhaving 2 to 10 carbon atoms, said polymer having a melt viscosity at190° C. of 1,000 to about 20,000 cp. when the polymer is polyethyleneand a melt viscosity at 190° C. of 1,000 to about 400,000 cp. when thepolymer is polypropylene or other higher polyolefin homo- or copolymer.In preferred embodiments of this invention, the melt viscosity of thecoating composition is at least 15,000 cp. and the copolymer isethylene/vinyl acetate.

McConnell et al. U.S. Pat. No. 3,524,759 does not disclose the use ofsimilar coating compositions for an extrusion coating process nor theuse of polyolefins and particularly polypropylene as coatablesubstrates. In the relevant art, curtain coating is a different anddistinct coating process from that of an extrusion coating process. Eachrequires coating compositions having very different rheologicalproperties. A principal limitation of curtain coating is that usefulcoating compositions must be sufficiently fluid to fall freely andsufficiently cohesive to present a continuous film to the substrate.

BRIEF DESCRIPTION OF THE INVENTION

It is an object of this invention to provide an extrusion coatingcomposition having good adhesion for polypropylene substrates andsatisfactory adhesion for other polyolefin substrates such as highdensity polyethylene substrates which can be applied at temperatures inthe range of about 500° F. to 580° F.

It is an object of this invention to provide a coating in whichtemperature sensitive fire retardants for polyolefin polymers can beincorporated and used without severe decomposition.

It is an object of this invention to provide a coating which provides asoft fabric hand. Where a soft fabric hand means flexibility and/or lackof stiffness as the term is used to describe the handle or feel offabrics.

It is an object of this invention to provide an extrusion coatingcomposition having a sufficiently high melt strength and/or elasticityto allow coating speeds in excess of 100 feet/min. while providing afinished coating of 1 mil or greater on polyolefin substrates that isvoid free.

Other objects of this invention are clear to one skilled in the artbased upon this Specification.

One embodiment of this invention is an extrusion coating compositionhaving a melt flow rate in the range of about 2-8 g/10 min. (ASTM D 1238Condition L) comprising:

(a) about 50-90% and preferably about 60-80% by weight of a terpolymercontaining reacted ethylene, propylene, and a diene, said terpolymerhaving a flow rate in the range of about 0.5 to 1.0 g/10 min. andpreferably in the range of about 0.6 to 0.7 g/10 min. (ASTM D-1238-70Condition L), wherein the diene is in a low concentration up to amaximum concentration in percent by weight of about 3% and is a monomerselected from the group consisting of 1,3-butadiene, isoprene,chloroprene, cyclooctadiene-1,5, dicyclopentadiene,cyclododecatriene-1,5,9, cyclododecadiene-1,7, cycloheptadiene-1,4,cyclohexadiene-1,4, norbornadiene, methylene-norbornene,methyl-tetrahydroindene, dimethyl-tetrahydroindene,6-methyl-heptadiene-1,5, hexadiene-1,4,6-methyl-4,7,8,9-tetrahydroindene, and ethylidene-norbornene, andwherein the reacted ethylene and propylene are in a ratio by weight ofabout 3:1,

(b) about 50-10% and preferably about 40-20% by weight of a high densitypolyethylene having a melt index in the range of about 0.2-30 g/10 min.and preferably in the range of about 10-20 g/10 min. (ASTM D-1238-65TCondition E), an unannealed density in the range of about 0.956-0.965, aweight average molecular weight in the range of about 50,000-200,000,and optionally

(c) one or more of the additional components selected from the groupconsisting of:

(1) about 0-10% and preferably about 0.5-5% by weight of an opacifiersuch as TiO₂ able to pass through a 200 mesh screen, and preferablythrough a 325 mesh screen,

(2) about 0-20% and preferably about 0.5-15% by weight of a fireretardant composition comprising one or more poly-halogenated organiccompounds and antimony trioxide,

(3) about 0-5% and preferably about 0.5-3% by weight of an ultravioletlight stabilizer for polyolefins such as nickel dibutyl dithiocarbamate,2-(2-hydroxy-5-t-octylphenyl)benzotriazole,2-(3'-tertbutyl-2'-hydroxy-5-methylphenyl)-5-chlorobenzotriazole,2-(3',5'-di-tertbutyl-2'-hydroxyphenyl)-5-chlorobenzotriazole,2-hydroxy-4-n-octyloxybenzophenone, bis[O-ethyl(3,5di-tertbutyl-4-hydroxybenzyl)]phosphonate, etc., and

(4) about 0-5% and preferably about 0.5-3% by weight of a colorantdispersible in polyolefins such as a high density polyethylene with amelt index in the range of about 0.2-30 g/10 min. and/or polypropylenewith a melt flow rate in the range of about 20-50 g/10 min.

Another embodiment of this invention is an extrusion coating compositionhaving a melt flow rate in the range of about 50-85 g/10 min. (ASTM D1238 Condition L) comprising:

(a) about 30-75% and preferably about 30-50% by weight of an olefinpolymer blend, disclosed in U.S. Pat. No. 3,887,640 (1975) which patentis incorporated herein by reference, this blend comprises about 40 to 99and preferably about 75 to 97 percent by weight of an ethylene-propyleneblock copolymer comprising at least about 80 percent by weightpolymerized propylene having a flow rate of about 15 dg/min. to 100dg/min. and preferably of about 25 dg/min. to 95 dg/min. as determinedby ASTM D-1238-62T and about 1 to 60 and preferably about 2.5 to 25percent by weight of polyethylene having a melt index recovery of atleast about 50 and a density greater than about 0.912,

(b) about 70-25% and preferably about 50-30% by weight of anethylene-isobutylacrylate copolymer having a flow rate in the range ofabout 50 to 90 g/10 min. (ASTM D-1238-70 Condition L) and a density at23° C. in the range of about 0.920-0.930, and comprising about 30% byweight of reacted isobutylacrylate and optionally,

(c) one or more of a variety of additional components selected from thegroup consisting of:

(1) about 0-10% and preferably about 0.5-5% by weight of an opacifiersuch as TiO₂ having a particle size able to pass through a 200 meshscreen and preferably through a 325 mesh screen,

(2) about 0-20% and preferably about 0.5-15% by weight of a fireretardant composition comprising one or more polyhalogenated organiccompounds and antimony trioxide,

(3) about 0-3% and preferably about 0.5-2% by weight of an ultravioletlight stabilizer such as nickel bis[O-ethyl(3,5di-tertbutyl-4-hydroxybenzyl)]phosphonate,2-(2-hydroxy-5-t-octylphenyl)benzotriazole,2-(3'-tertbutyl-2'-hydroxy-5-methylphenyl)-5-chlorobenzotriazole,2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)-5-chlorbenzotriazole,2-hydroxy-4-n-octyloxybenzophenone, etc., and

(4) about 0-5% and preferably about 0.5-3% by weight of a colorantdispersible in polyolefins, such as high density polyethylene having amelt index in the range of about 0.20 to 30 g/10 min. and/orpolypropylene with a melt flow rate in the range of 20 to 50 g/10 min.

Still another embodiment of this invention is an extrusion coatingcomposition having a melt flow rate in the range of about 20-30 g/10min. (ASTM D 1238 Condition L) comprising:

(a) about 30-50% and preferably about 35-45% by weight of anethylene-isobutylacrylate copolymer having a flow rate in the range ofabout 50-90 g/10 min. (ASTM D-1238-70 Condition L), and a density at 23°C. in the range of about 0.920-0.930, and comprising about 30 percent byweight of reacted isobutylacrylate,

(b) about 10-40% and preferably about 25-35% by weight of a terpolymercomprising reacted ethylene, propylene, and a diene, said terpolymerhaving a flow rate in the range of about 0.5 to 1.0 g/10 min. andpreferably in the range of about 0.6 to 0.7 g/10 min. (ASTM D-1238-70Condition L), wherein the diene is in a low concentration up to amaximum concentration in percent by weight of about 3% and is a monomerselected from the group consisting of 1,3-butadiene, isoprene,chloroprene, cyclooctadiene-1,5, dicyclopentadiene,cyclododecatriene-1,5,9, cyclododecadiene-1,7, cycloheptadiene-1,4,cyclohexadiene-1,4, norbornadiene, methylene-norbornene,methyl-tetrahydroindene, dimethyl-tetrahydroindene,6-methylheptadiene-1,5, hexadiene-1,4,6-methyl-4,7,8,9-tetrahydroindene, and ethylidene-norbornene, andwherein the reacted ethylene and propylene are in a ratio by weight ofabout 3:1,

(c) about 10-40% and preferably about 25-35% by weight of a high densitypolyethylene having a melt index in the range of about 0.2-30 g/10 min.and preferably in the range of about 10-20 g/10 min. (ASTM D-1238-65TCondition E), an unannealed density in the range of about 0.956-0.965, aweight average molecular weight in the range of about 50,000-200,000,and optionally,

(d) one or more of the additional components selected from the groupconsisting of:

(1) about 0-10% and preferably about 0.5-5% by weight of an opacifiersuch as TiO₂ able to pass through a 200 mesh screen, and preferablythrough a 325 mesh screen,

(2) about 0-20% and preferably about 0.5-15% by weight of a fireretardant composition comprising one or more polyhalogenated organiccompounds and antimony trioxide,

(3) about 0-3% and preferably about 0.5-2% by weight of an ultravioletlight stabilizer for polyolefins such as nickel dibutyl dithiocarbamate,2-(2-hydroxy-5-t-octylphenyl)benzo-triazole,2-(3'-tertbutyl-2'-hydroxy-5-methylphenyl)-5-chlorobenzotriazole,2-(3',5'-di-tertbutyl-2'-hydroxyphenyl)-5-chlorobenzotriazole,2-hydroxy-4-n-octyloxy-benzophenone, nickelbis(O-ethyl(3,5-di-tertbutyl-4-hydroxybenzyl))phosphonate, etc., and

(4) about 0-5% and preferably about 0.5-3% by weight of a colorantdispersible in polyolefins such as high density polyethylene having amelt index in the range of about 0.20 to 30 g/10 min. and/orpolypropylene having a melt flow rate in the range of about 20 to 50g/10 min.

The fire retardant composition comprising one or more polyhalogenatedorganic compounds and antimony trioxide referred to in the abovedescribed compositions is additionally defined hereinafter. U.S. patentsincorporated herein by reference disclosing polyhalogenated organiccompounds that are known to be useful in combination with antimonytrioxide so as to impart fire retardancy to resinous polyolefincompositions containing them are: U.S. Pat. Nos. 3,275,596 (1966),3,403,036 (1968), 3,419,518 (1968), and 3,738,958 (1973). Thesehalogenated organic compounds are preferably characterized as:

1. being substantially non-volatile from a resionous polyolefin polymermatrix at the approximate melting point of a polymer compositioncomprising said resinous polyolefin polymer, antimony trioxide, and saidhalogenated organic compounds,

2. having a gram molecular weight above about 200; and

3. a halogen content in percent by weight of the halogenated compound inthe range of about 35-93% wherein the halogen is selected from the groupconsisting of chlorine and bromine.

Other ultraviolet light stabilizers for polyolefins which can be used inthe above described compositions can be found in the following U.S.patents incorporated herein by reference: U.S. Pat. Nos. 3,935,163(1976), 3,919,234 (1975), 3,917,672 (1975), 3,936,418 (1976), and3,932,324 (1976).

The above disclosed embodiments are generally prepared by a process offirst forming a physical blend and then melt mixing that physical blend.The process of forming a physical blend involves physically weighing andthen blending the appropriate components in a twin shell type blenderand/or a Nauta Mixer for about 20 to 30 minutes and/or until a gooddispersion of the physical blend is achieved. The process of melt mixinginvolves melting the composite blend in a compounding extruder having ascrew with an L/D of about 24/1 or about 30/1 at a temperature throughthe barrel of 300°±5° F. with flange and adapter at 350°±5° F. The dieis set at 375°±5° F. The compounding extruder is equipped with a mixingscrew which ensures good melt mixing of the component parts of thephysical blend. Back pressure and additional melt mixing is achieved byutilizing a series of metal screens, the smallest of which can rangefrom about 100 to 325 in mesh size. The melt is forced through thescreens and then through an appropriate die opening. The resultingindividual strands are water quenched at temperatures of about 60° to70° F. and subsequently cold cut to form individual pellets. Thefinished product then can be post blended if desired.

It is to be noted that in spite of apparent differences between theindividual polymer components, they are surprisingly compatible in themelt phase in all of the above disclosed compositions.

The process of extrusion coating one of the above disclosed compositionsinvolves extruding a molten film from a die having a slit opening in therange of about 1 to 20 mils. An extrusion pressure within this die is inthe range of about 1,000 to 1,500 psi. The film as it exits the die isat a temperature in the range of about 500° F. to 580° F. This extrudedfilm is then contacted with a woven or non-woven polyolefin substrate,to which a satisfactory bond therebetween can be made (see Example 4),at or just before the nip of two counter rotating rolls having diametersin the range of about 4-12 inches. A pressure in the range of about 100to 200 lbs./linear inch is applied in the nip. The temperature of thechill roll is in the range of about 50°-70° F. The rate of speed of acoated substrate through the nip is in the range of about 100 to 160ft/minute when a 1 mil thick coating is being applied.

DETAILED DESCRIPTION OF THE INVENTION EXAMPLE 1

A physical blend was formed by physically weighing 41 grams of Eastman'sethylene-propylene copolymer (499-P), 40 grams of DuPont'sethylene-isobutylacrylate (3647-2), 9 grams of a fire retardantadditive, 8 grams of a dispersible pigment and 2 grams of an ultravioletlight stabilizer each described in TABLE 1 into a Nauta mixer and mixingthis blend for about 25 minutes. This physical blend was subsequentlymelt mixed by melting said physical blend in a compounding extruder witha screw having an L/D of 30/1 at a temperature through the barrel ofabout 300° F. with flange and adapter at about 350° F. and the die setat about 375° F. A back pressure is achieved by a series of metalscreens having a mesh size of 325. The extrudate having a flow rate ofabout 62 g/10 min. (ASTM D 1238 Condition L) is in the form of strandswhich are water quenched at about 65° F. and cut to form individualpellets.

TABLE 1 discloses four examples of typical compositions made asdescribed above. TABLE 2 gives the machine settings utilized whileemploying the compositions of TABLE 1 to form a coating of about one milon a delustered polyolefin fiber substrate. The polyolefin fibersubstrate was made either from Amoco 10-5156, a high ultraviolet lightstabilized polypropylene, or from a general purpose resin containing ahomopolymer of polypropylene and a general purpose stabilizer system, orfrom Amoco 30-605-A2, a high density polyethylene.

                  TABLE 1                                                         ______________________________________                                                           1    2      3      4                                       ______________________________________                                        Eastman's ethylene-propylene                                                  copolymer 499-P      41.0   30.0   75.0 40.0                                  DuPont's ethylene isobutyl-                                                   acrylate 3647-2      40.0   70.0   25.0 35.0                                  *Fire retardant additive                                                                           9.0    0      0    15.0                                  **Colorant           8.0    0      0    8.0                                   ***ultraviolet light stabilizer                                                                    2.0    0      0    2.0                                   ______________________________________                                         *Fire retardant additive contains about 60% by weight of decabromodipheny     oxide and Sb.sub.2 O.sub.3 in a ratio of about 2.1:1 and about 40% by         weight of high density polyethylene having a melt flow rate of about 12       (ASTM D1238).                                                                 **Colorant includes a mixture of TiO.sub.2 and a blue pigment wherein         about 3 parts by weight is TiO.sub.2 to about 5 parts by weight of blue       pigment is used.                                                              ***Ultraviolet light stabilizer is a 2:1 chelate of nickel employing an       alkylated phenol phosphonate wherein 15% by weight is stabilizer and 85%      by weight is polypropylene and/or high density polyethylene.             

                  TABLE 2                                                         ______________________________________                                        Extrusion Rate: 320 lbs./hr.                                                  Extruder: -                                                                          screw size: 31/2 inches                                                rate of rotation of screw: 135 rpm                                            barrel temperature: Profile from 400° to 540° F.                plastic pressure on extrusion: 1200 psi                                       plastic temperature on extrusion: 530° ± 15° F.              extruder die opening: 20 Mils                                                 *Air gap: 23/4 inches                                                         Pressure at nip: 125 lbs/linear inch                                          Temperature of chill roll: 55° ± 5° F.                       Rate of movement of a polypropylene web: 110 ft/minute                        ______________________________________                                         *Air gap is the distance between the extruder die opening and the nip         created by a chill roll and a pressure roll.                             

EXAMPLE 2

DuPont's 3391 ethylene-propylene-diene hydrocarbon terpolymer rubber andAmoco's 30-680-B4 high density polyethylene are first blended and thenmelt mixed as discussed in Example 1 alone or with various pigments,flame retardants, and ultraviolet light stabilizers to form variouscoating compositions.

TABLE 3 discloses three examples of such coating compositions. TABLE 4gives the machine settings utilized while employing the coatingcompositions of TABLE 3 to form an approximately 3 mil coating on awoven polyolefin fiber substrate. The polyolefin fiber substrate usedwas made from either Amoco resin 10-5156 (polypropylene) or Amoco resin10-5013 (high density polyethylene).

                  TABLE 3                                                         ______________________________________                                                           1     2       3                                            ______________________________________                                        *Ethylene-propylene-diene terpolymer                                                               85.0    50.0    60.0                                     **High density polyethylene                                                                        15.0    50.0    15.0                                     ***Colorant          0       0       3.0                                      TiO.sub.2            0       0       5.0                                      ***Fire retardant concentrate                                                                      0       0       15.0                                     ****Ultraviolet stabilizer concentrate                                                             0       0       2.0                                      ______________________________________                                         *Ethylene-propylene-diene terpolymer obtainable from DuPont under the nam     ethylenepropylene-diene hydrocarbon rubber 3391.                              **High density polyethylene is obtainable from Amoco, under the name high     density polyethylene 30680-B4 having a melt flow rate of about 12.            ***See TABLE 1.                                                               ****Nickel dibutyl dithiocarbamate and/or alkylated phenol phosphate          wherein 10 to 15% by weight is stabilizer and 85 to 90% by weight is          polypropylene and/or high density polyethylene.                          

                  TABLE 4                                                         ______________________________________                                        Extrusion rate: 216 lbs/hr.                                                   Extruder:                                                                      screw size: 31/2 inches                                                      rate of rotation of screw: 105 rpm                                            barrel temperature: profile from 420° to 575° F.                plastic pressure on extrusion: 1200 psi                                       plastic temperature on extrusion: 550° ± 10° F.              extruder die opening: 20 mils                                                 *Air gap: 23/4 inches                                                         Pressure at nip: 135 lbs/linear inch                                          Temperature of chill roll: 55° ± 5° F.                       Rate of movement of a polypropylene web: 50 ft./min.                          ______________________________________                                         *Air gap is the distance between the extruder die opening and the nip         created by a chill roll and pressure roll.                               

EXAMPLE 3

About 29.8% by weight of DuPont's ethylene-propylene-diene hydrocarbonrubber 3391, about 38,6% by weight of DuPont's ethylene-isobutylacrylate3647-2, about 29.6% by weight Amoco's polyethylene 30-680-B4, and about2% by weight of the ultraviolet stabilizer used in TABLE 1 areformulated as disclosed in Example 1. The finished composition has aflow rate of about 23 g/10 min. (ASTM D 1238 Condition L). The machinesettings utilized for this coating composition to form an approximately1 mil coating on a delustered woven polyolefin fiber substrate are givenin TABLE 5. The polyolefin fiber substrate used is the same as describedin Example 1.

                  TABLE 5                                                         ______________________________________                                        Extrusion rate: 320 lbs./hr.                                                  Extruder:                                                                      screw size: 31/2 inches                                                      rate of rotation of screw: 135 rpm                                            barrel temperature: profiled from 425° to 550° F.               plastic pressure on extrusion: 1200 psi                                       plastic temperature on extrusion: 545° ± 10° F.              extruder die opening: 20 mils                                                 *Air gap: 23/4 inches                                                         Pressure at nip: 130 lbs/linear inch                                          Temperature of chill roll: 55° ± 5° F.                       Rate of movement of the woven polypropylene web: 140 ft./min.                 ______________________________________                                         *Air gap is the distance between the extruder die opening and the nip         created by a chill roll and pressure roll.                               

EXAMPLE 4

The coated woven polyolefin substrates produced in examples 1, 2, and 3are discussed in more detail hereinafter. The fabrics were in all casesdelustered, however, non-delustered fabrics can also be used.

In the case of the Amoco resin 10-5156 and the general purpose resin,the fabric had 24 warp fibers/inch×7 weft fibers/inch. The warp fiberswere 1.9 mils thick and 50 mils wide and had a denier of 500±100. Theweft fibers were 2.1 mils thick and 95 mils wide and had a denier of1050.

In the case of the Amoco resin 30-605-A2, a high density polyethylene,the fabric had 10 warp fibers/inch×7 weft fibers/inch. Both the warp andweft fibers had a denier of 1000 and were 2 mils thick and 100 milswide.

A qualitative test to determine the adhesion for all coatings to allsubstrates was:

1. to apply to the coated side of a fabric a pressure sensitive silverduck tape obtainable from Borden Chemical, Northfield, Illinois, havingdimensions 2"×8" with about a 1/2" unbonded end under a pressure ofabout 20-30 psi/linear inch in the nip between two rollers, and then

2. to remove said tape by a rapid pull.

If more than about 50% of the coating is removed then the coating isconsidered poor and unsatisfactory. It is readily apparent that if thecoating is slick or waxy so as not to form a good bond to the pressuresensitive tape the results will vary. It is also to be expected that aparticular coating will not bond with equal strength to all substrates.

In all examples disclosed, the coatings had an adhesion which was atleast satisfactory.

EXAMPLE 5

The melt viscosity with Rabinowitsch correction included was determinedat 190° C. in an Instron MCER rheometer for compositions A, B, and Cgiven in TABLE 6. These compositions were formulated with the proceduredisclosed in Example 1. A capillary die having an L/D of 33 was used forsamples A, and B(1) and a capillary die having an L/D of 66 was used forall other samples. The observed viscosity of the above blends ofpolymers are shear independent (Newtonian) at shear rates below about 1sec⁻¹, but shear thinning above about 1 sec⁻¹. Outside of the shearindependent range it is necessary to define both the shear rate and thecorresponding apparent viscosity. TABLE 7 lists both the apparentviscosity in centipoise and the corresponding shear rate for thecompositions of TABLE 6.

From TABLE 7, it is clear that the disclosed compositions are shearthinning and that the shear independent viscosity in centipoise at lowshear rates for compositions A, B(1), B(2), B(3) and C(1), C(2) and C(3)are greater than 3.8×10⁵, 6.6×10⁵, 1.7×10⁶, 6.7×10⁵, 2.9×10⁶, 3.5×10⁶,and 6.1×10⁶ centipoise, respectively.

The examples disclosed are specific illustrations of this invention, butvariations on them are apparent to those skilled in the art and suchvariations are intended to be within the scope of this invention.

                  TABLE 6                                                         ______________________________________                                        Composition A        Percent by Weight                                        ______________________________________                                        Ethylene-Propylene Copolymer                                                                       40%                                                      Ethylene-Isobutylacrylate Copolymer                                                                40.8%                                                    DuPont 3647-2                                                                 Fire Retardant Concentrate                                                                         9.0%                                                     see TABLE 1, infra                                                            Ultraviolet Light Stabilizer                                                                       2.0%                                                     see TABLE 1, infra                                                            Colorant             8.2%                                                     see TABLE 1, infra                                                            ______________________________________                                                           Percent by Weight                                          Composition B        1       2       3                                        ______________________________________                                        Ethylene-Isobutylacrylate Copolymer                                                                33%     24.3%   40.5%                                    DuPont 3647-2                                                                 Ethylene Propylene Diene                                                                           24%     32.4%   8.1%                                     Modified Terpolymer                                                           DuPont EPDM LD-3391                                                           High Density Polyethylene                                                                          24%     24.3%   32.4%                                    Amoco 30-680-B4 HDPE                                                          Fire Retardant Concentrate                                                                         9.0%    9.0%    9.0%                                     see TABLE 1, infra                                                            Ultraviolet Light Stabilizer                                                                       2.0%    2.0%    2.0%                                     see TABLE 1, infra                                                            Colorant             8.0%    8.0%    8.0%                                     ______________________________________                                        Composition C        1       2       3                                        ______________________________________                                        Ethylene Propylene Diene                                                      Modified Terpolymer  40.5%   56.7%   72.9%                                    DuPont EPDM LD-3391                                                           High Density Polyethylene                                                                          40.5%   24.3%   8.1%                                     Amoco 30-680-B4 HDPE                                                          Fire Retardant Concentrate                                                                         9.0%    9.0%    9.0%                                     See TABLE 1, infra                                                            Colorant             8.0%    8.0%    8.0%                                     Chemtron 1784-1                                                               Ultraviolet Light Stabilizer                                                                       2.0%    2.0%    2.0%                                     see TABLE 1, infra                                                            ______________________________________                                    

                  TABLE 7                                                         ______________________________________                                                        Shear Rate     Viscosity                                                      (sec.sup.-1)   (centipoise)                                   ______________________________________                                        Composition A   1.6 × 10 3.8 × 10.sup.5                                           4.0 × 10 2.5 × 10.sup.5                                           8.1 × 10 1.9 × 10.sup.5                                           1.65 × 10.sup.2                                                                        1.4 × 10.sup.5                                           4.3 × 10.sup.2                                                                         9.0 × 10.sup.4                                           8.8 × 10.sup.2                                                                         6.2 × 10.sup.4                                           1.75 × 10.sup.3                                                                        4.4 × 10.sup.4                                           4.49 × 10.sup.3                                                                        2.5 × 10.sup.4                                           9.0 × 10.sup.3                                                                         1.7 × 10.sup.4                                           1.8 × 10.sup.4                                                                         1.15 × 10.sup.4                          ______________________________________                                        Composition B                                                                 1            2             3                                                  Shear  Viscosity Shear    Viscosity                                                                            Shear  Viscosity                             Rate   (centi-   Rate     (centi-                                                                              Rate   (centi-                               (sec.sup.-1)                                                                         poise)    (sec.sup.-1)                                                                           poise) (sec.sup.-1)                                                                         poise)                                ______________________________________                                        1.5 × 10                                                                       6.6 × 10.sup.5                                                                    1.8 × 10.sup.0                                                                   1.7 × 10.sup.6                                                                 1.8 × 10.sup.0                                                                 6.7 × 10.sup.5                  3.8 ×  10                                                                      4.7 × 10.sup.5                                                                    4.7 × 10.sup.0                                                                   1.3 × 10.sup.6                                                                 4.5 × 10.sup.0                                                                 6.0 × 10.sup.5                  7.8 × 10                                                                       3.6 × 10.sup.5                                                                    9.6 × 10.sup.0                                                                   1.0 × 10.sup.6                                                                 9.2 × 10.sup.0                                                                 4.8 × 10.sup.5                  1.6 × 10.sup.2                                                                 2.7 × 10.sup.5                                                                    2.0 × 10.sup.1                                                                   8.0 × 10.sup.5                                                                 1.9 × 10.sup.1                                                                 4.1 × 10.sup.5                  4.2 × 10.sup.2                                                                 1.8 × 10.sup.5                                                                    5.0 × 10.sup.1                                                                   5.6 × 10.sup.5                                                                 4.8 × 10.sup.1                                                                 3.0 × 10 .sup.5                 8.6 × 10.sup.2                                                                 1.25 × 10.sup.5                                                                   1.0 × 10.sup.2                                                                   4.2 × 10.sup.5                                                                 9.7 × 10.sup.1                                                                 2.4 × 10.sup.5                  1.8 × 10.sup.3                                                                 8.60 × 10.sup.4                                                                   2.1 × 10.sup.2                                                                   3.0 × 10.sup.5                                                                 2.0 × 10.sup.2                                                                 1.8 × 10.sup.5                  4.8 × 10.sup.3                                                                 4.6 × 10.sup.4                                                                    5.3 × 10.sup.2                                                                   2.0 × 10.sup.5                                                                 5.0 × 10.sup. 2                                                                1.3 × 10.sup.5                  1.0 × 10.sup.4                                                                 3.0 × 10.sup.4                                                                    1.1 × 10.sup.3                                                                   1.4 × 10.sup.5                                                                 1.0 × 10.sup.3                                                                 9.1 × 10.sup.4                  2.0 × 10.sup.4                                                                 1.85 × 10.sup.4                                                                   2.2 × 10.sup.3                                                                   9.0 × 10.sup.4                                                                 2.1 × 10.sup.3                                                                 6.6 × 10.sup.4                  ______________________________________                                        Composition C                                                                 1            2             3                                                  Shear  Viscosity Shear    Viscosity                                                                            Shear  Viscosity                             Rate   (centi-   Rate     (centi-                                                                              Rate   (centi-                               (sec.sup.-1)                                                                         poise)    (sec.sup.-1)                                                                           poise) (sec.sup.-1)                                                                         poise)                                ______________________________________                                        1.8 × 10.sup.0                                                                 2.9 × 10.sup.6                                                                    1.9 × 10.sup.0                                                                   3.5 × 10.sup.6                                                                 2.0 × 10.sup.0                                                                 6.1 × 10.sup.6                  4.8 × 10.sup.0                                                                 2.3 × 10.sup.6                                                                    5.0 × 10.sup.0                                                                   2.4 × 10.sup.6                                                                 5.2 × 10.sup.0                                                                 3.7 × 10.sup.6                  9.8 × 10.sup.0                                                                 1.6 × 10.sup.6                                                                    1.0 × 10.sup.1                                                                   1.7 × 10.sup.6                                                                 1.1 × 10.sup.1                                                                 2.6 × 10.sup.6                  2.0 × 10.sup.1                                                                 1.2 × 10.sup.6                                                                    2.1 × 10.sup.1                                                                   1.2 × 10.sup.6                                                                 2.2 × 10.sup.1                                                                 1.8 × 10.sup.6                  5.2 × 10.sup.1                                                                 3.0 × 10.sup.5                                                                    5.4 × 10.sup.1                                                                   7.2 × 10.sup.5                                                                 5.6 × 10.sup.1                                                                 1.1 × 10.sup.6                  1.1 × 10.sup.2                                                                 5.7 × 10.sup.5                                                                    1.1 × 10.sup.2                                                                   5.1 × 10.sup.5                                                                 1.1 × 10.sup.2                                                                 7.7 × 10.sup.5                  2.2 × 10.sup.2                                                                 4.0 × 10.sup.5                                                                    2.3 × 10.sup.2                                                                   3.3 × 10.sup.5                                                                 2.3 × 10.sup.2                                                                 5.3 × 10.sup.5                  5.6 × 10.sup.2                                                                 2.5 × 10.sup.5                                                                    5.7 × 10.sup.2                                                                   2.0 × 10.sup.5                                                                 5.8 × 10.sup.2                                                                 3.2 × 10.sup.5                  1.1 × 10.sup.3                                                                 1.6 × 10.sup.5                                                                    1.2 × 10.sup.3                                                                   1.3 × 10.sup.5                                                                 1.1 × 10.sup.3                                                                 2.1 × 10.sup.5                  2.3 × 10.sup.3                                                                 1.0 × 10.sup.5                                                                    2.3 × 10.sup.3                                                                   9.1 × 10.sup.4                                                                 2.3 × 10.sup.3                                                                 1.3 × 10.sup.5                  ______________________________________                                    

The invention which is claimed is:
 1. An extrusion coating compositionfor woven and nonwoven polyolefin substrates comprising:(a) about 50-90%by weight of a terpolymer containing reacted ethylene, propylene, and adiene, said terpolymer having a flow rate in the range of about 0.5 to1.0 g/10 min., wherein the diene is in a low concentration up to amaximum concentration in percent by weight of about 3% and is a monomerselected from the group consisting of 1,3-butadiene, isoprene,chloroprene, cyclooctadiene-1,5, dicyclopentadiene,cyclododecatriene-1,5,9, cyclododecadiene-1,7, cycloheptadiene-1,4,cyclohexadiene-1,4, norbornadiene, methylene-norbornene,methyl-tetrahydroindene, dimethyl-tetrahydroindene,6-methyl-heptadiene-1,5, hexadiene-1,4,6-methyl-4,7,8,9-tetrahydroindene, and ethylidene-norbornene, andwherein the reacted ethylene and propylene are in a ratio by weight ofabout 3:1; (b) about 50-10% by weight of a high density polyethylenehaving a flow rate of about 0.2-30 g/10 min., an unannealed density inthe range of about 0.956-0.965, and a weight average molecular weight inthe range of about 50,000-200,000; (c) about 0.5-5% by weight of anopacifier; (d) about 0.5-15% by weight of a fire retardant compositioncomprising at least one polyhalogenated organic compound and antimonytrioxide; (e) about 0.5-3% by weight of an ultraviolet light stabilizerfor polyolefins; andwherein said composition has a shear independentmelt viscosity at 190° C. of above about 2.9×10⁶ centipoise.
 2. Thecomposition of claim 1 wherein said ultraviolet light stabilizercomprises a 2:1 chelate of nickel coordinated to an alkylated phenolphosphonate wherein the alkyl comprises up to 12 carbons, and the fireretardant comprises decabrromodiphenyl oxide and Sb₂ O₃ in a ratio ofabout 2.1:1.
 3. The composition of claim 1 wherein the ultraviolet lightstabilizer comprises a 2:1 chelate of nickel coordinated to an alkylatedphenol phosphonate wherein the alkyl comprises up to 12 carbons, and thefire retardant comprises decabromodiphenyl oxide and Sb₂ O₃ in a ratioof about 2.1:1.
 4. The composition of claim 1 wherein said opacifier isTiO₂.
 5. An extrusion coating composition for woven and nonwovenpolyolefin substrates comprising:(a) about 30-50% by weight of anethylene-isobutylacrylate copolymer having a flow rate in the range ofabout 50-90 g/10 min., a density at 23° C. in the range of about0.920-0.930, and comprising about 30% by weight of reactedisobutylacrylate; (b) about 10-40% by weight of a terpolymer comprisingreacted ethylene, propylene, and a diene, said terpolymer having a flowrate in the range of about 0.5 to 1.0 g/10 min., wherein the diene is ina low concentration up to a maximum concentration in percent by weightof about 3% and is a monomer selected from the group consisting of1,3-butadiene, isoprene, chloroprene, cyclooctadiene-1,5,dicyclopentadiene, cyclododecatriene-1,5,9, cyclododecadiene-1,7,cycloheptadiene-1,4, cyclohexadiene-1,4, norbornadiene,methylenenorbornene, methyl-tetrahydroindene, dimethyl-tetrahydroindene,6-methyl-heptadiene-1,5, hexadiene-1,4,6-methyl-4,7,8,9-tetrahydroindene, and ethylidene-norbornene, andwherein the reacted ethylene and propylene are in a ratio by weight ofabout 3:1; (c) about 10-40% by weight of a high density polyethylenehaving a flow rate in the range of about 0.2-30 g/10 min., an unannealeddensity in the range of about 0.956-0.965, a weight average molecularweight in the range of about 50,000-200,000; (d) about 0.5-5% by weightof an opacifier; (e) about 0.5-15% by weight of a fire retardantcomposition comprising at least one polyhalogenated organic compound andantimony trioxide; (f) about 0.5-3% by weight of an ultraviolet lightstabilizer; andwherein said composition has a shear independent meltviscosity at 190° C. of above about 660,000 centipoise.
 6. Thecomposition of claim 5 wherein said opacifier is TiO₂.
 7. An extrusioncoating composition for woven and nonwoven polyolefin substratesselected from the group consisting of:(1) a composition with a shearindependent melt viscosity at 190° C. above about 2.9×10⁶ centipoisecomprising:(a) about 50-90% by weight of a terpolymer containing reactedethylene, propylene, and a diene, said terpolymer having a flow rate inthe range of about 0.5 to 1.0 g/10 min., wherein the diene is in a lowconcentration up to a maximum concentration in percent by weight ofabout 3% and is a monomer selected from the group consisting of1,3-butadiene, isoprene, chloroprene, cyclooctadiene-1,5,dicyclopentadiene, cyclododecatriene-1,5,9, cyclododecadiene-1,7,cycloheptadiene-1,4, cyclohexadiene-1,4, norbornadiene,methylenenorbornene, methyl-tetrahydroindene, dimethyl-tetrahydroindene,6-methyl-heptadiene-1,5, hexadiene-1,4,6-methyl-4,7,8,9-tetrahydroindene, and ethylidenenorbornene, and whereinthe reacted ethylene and propylene are in a ratio by weight of about3:1; (b) about 50-10% by weight of a high density polyethylene having aflow rate of about 0.2-30 g/10 min., an unannealed density in the rangeof about 0.956-0.965, and a weight average molecular weight in a rangeof about 50,000-200,000; (c) about 0.5-5% by weight of an opacifier; (d)about 0.5-15% by weight of a fire retardant composition comprising atleast one polyhalogenated organic compound and antimony trioxide; (e)about 0.5-3% by weight of an ultraviolet light stabilizer forpolyolefins; and (2) a composition having a shear independent meltviscosity at 190° C. of above about 660,000 centipoise comprising:(a)about 30-50% by weight of an ethylene-isobutylacrylate copolymer havinga flow rate in the range of about 50-90 g/10 min., a density at 23° C.in the range of about 0.920-0.930, and comprising about 30% by weight ofreacted isobutylacrylate, (b) about 10-40% by weight of a terpolymercontaining reacted ethylene, propylene, and a diene, said terpolymerhaving a flow rate in the range of about 0.5 to 1.0 g/10 min., whereinthe diene is in a low concentration up to a maximum concentration inpercent by weight of about 3% and is a monomer selected from the groupconsisting of 1,3-butadiene, isoprene, chloroprene, cyclooctadiene-1,5,dicyclopentadiene, cyclododecatriene-1,5,9, cyclododecadiene-1,7,cycloheptadiene-1,4, cyclohexadiene-1,4, norbornadiene,methylene-norbornene, methyl-tetrahydroindene,dimethyl-tetrahydroindene, 6-methyl-heptadiene-1,5, hexadiene-1,4,6-methyl-4,7,8,9-tetrahydroindene, and ethylidene-norbornene, andwherein the reacted ethylene and propylene are in a ratio by weight ofabout 3:1, and (c) about 10-40% by weight of a high density polyethylenehaving a flow rate in the range of about 0.2-30 g/10 min., an unannealeddensity in the range of about 0.956-0.965, and a weight averagemolecular weight in a range of about 50,000-200,000; (d) about 0.5-5% byweight of an opacifier; (e) about 0.5-15% by weight of a fire retardantcomposition comprising at least one polyhalogenated organic compound andantimony trioxide; (f) about 0.5-3% by weight of an ultraviolet lightstabilizer.
 8. The composition of claim 7 wherein said opacifier isTiO₂.